Corrosion Behavior Comparison of Ti-6Al-4V Produced by Electron Beam Melting and Traditional Wrought Processes

Additive manufacturing (AM) is becoming an effective solution in medical, marine and aerospace applications. However, limited studies combine electrochemical data with microstructural characterization for traditional and AM-built alloys; fewer still consider corrosion mechanisms. The nature of the laser beam interaction with the part results in rapid heating and solidification cycles and distinct microstructures of AM printed prats including columnar grain structures with evidence of extended solubility phases fields, and nonequilibrium phases. In the present study, the corrosion behavior of Ti-6Al-4V alloys produced by electron beam melting (EBM) and traditional wrought processes was compared. Different AM build directions and heat treatments were performed to determine the relationship between microstructure and corrosion behavior. The characterization of microstructure and surface oxide layers includes OLM, SEM, EDS, XRD and XPS. Electrochemical methods include OCP, EIS and potential-static polarization (PSP). The results of this study provide insight on the corrosion mechanisms for passivating alloys produced by AM.